Hi, I proccessed some ram fingers in HNO3, seperated them and water washed untill all blue was gone then put the foils into a clean vessil added HCI and then HNO3 untill reaction started let dissolve then added a button. The button wheighed in at 1.28 grams left it in for half hour and removed and put back on the scales still 1.28 grams. I then added water and then SMB let sit overnight. The gold dropped as it should and I then vaccumed of as much of the liquid as I could before adding alittle more water (tap water). Then I put on the heat to get rid of the last of the liquid all was fine untill the liquid was nearly gone and then it dissolved some of the powder turning the liquid bright yellow. Im thinking just add water re-drop with SMB and start again but Im puzzled on why it would take back the gold powder, please someone fill me in.
gold powder dissolving???????
- Thread starter rotorpowa
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Geo
Well-known member
when you evaporated the acid, it concentrated it to the point it was able to dissolve the gold again. when it was diluted you were able to precipitate the gold. next time when you add the button of gold, warm the solution and see if it starts to react.
Ok, thanks Geo. Im now thinking that the HNO3 should be all used up as it did not take back all of the powder, would I be correct in my assumption? I really wanted to melt the powder today and not wait for it to drop again oh well I guess thats just the way the cookie crumbles.
Geo
Well-known member
not normally. gold will evaporate after the nitric and it really has to be hot. as the solution concentrates,the boiling point rises.if you keep the solution below a boil, you shouldn't lose gold until the solution gets really thick.
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Geo said:
Yep!
If you guys don't mind a comment---I'll never understand how any of you achieve even modest success by working with acids at room temperatures. The problems that you experience could be nicely addressed simply by heating. The only exception to that is if you allow days for dissolution when you'd have accomplished the mission in a few minutes, using heat.
You really should try adding heat to the processes. You'll never go back to working without.
Confused, I remain,
Harold
Hey Harold, Thanks for chiming in although I left it out I did work with heat, but I must admit when I added the button I had taken it off the heat. I dont think it would have been quite room temp but still not really a heated, I will remember in future heat is my friend. I added the Smb to re-drop and left for a few hours untill it looked clear of floaty's, some of the dropped gold looked like gold bright and not like the brown powder I would expect. I took off the liquid into another vessel to let sit for longer then managed to evaporate off the rest although it left behind a white residue and I only ended up with a .3 gram button. I really thought from the material I did it would have been more but I did make mistakes. The ram sticks before defingering filled a 4 litre ice-cream bucket not sure of the weight scales are not working ATM. Oh and there is nothing else dropping in the other vessel. I now have these foils in AR and Im scared to take it further
rotorpowa,
Nice recovery of foils, do not be scared, but do be prepared, read up on the HCl/bleach method, and testing with stanous chloride, some practice in testing if you have not done it before will also help you to be prepared.
Nice recovery of foils, do not be scared, but do be prepared, read up on the HCl/bleach method, and testing with stanous chloride, some practice in testing if you have not done it before will also help you to be prepared.
Thanks Butcher, its funny really I am finding more expensive to use the other methods. I got 20ltrs of nitric and 20 of hydrocloric for under $140 so I have plenty to use. I have although looked up some of the other methods and purchased some peroxide 6% but I could only get 100ml bottles they are trying to get in bigger but I will have to see how to goes. I have been using old coffee pots etc and have had a lot of trouble with things braking spilling ect and Im fed up with this so I have decided this batch is my last until I visit my supplies store and get some real beakers etc. I have spent most of the day trying to get this ar to evaporate of the nitric with little success and Im getting very frustrated, I added a small button .33grams to the ar so I could see when the reaction stopped but all day it has been very slowly reducing in size. Im having trouble getting enough heat, Im using a old electric frying pan with a thermostat and cant get it to even slightly bubble, the ar that is the button has small bubbles steadily rising from it. I talking over 5 hrs now and man I really want to see how much gold I get from these foils but dont want to rush things. I looked into using urea but I dont like what Freechemist had to say about that and was worried myself about what containments to would create. I though this would have been much easier but man was I wrong.
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Proof that you have excess nitric.rotorpowa said:
Even without excessive heat, if you provide greater surface area, the free nitric will be consumed all the faster. In the future, flatten the button well, or add larger buttons. What ever it takes to provide greater surface area. Considering you're at the finishing stages of processing, while it may tie up some of your values, it's only briefly. I used to keep several ounces of buttons on hand just for this purpose.
Remember that exhausting either nitric of HCl will result in cessation of dissolution. When activity at the button ceases, add a little free HCl to ensure that you have consumed the nitric. If you have not, action will begin once again. If you have, no big deal. Free HCl does no harm.
Harold
Hey Harold,
I guess Im on the right track I just came in after adding a larger button 1.28 grams that was flat lol. I also worked out why I could not get enough heat, the thermostat had been played with so I have adjusted it to provide more than enough heat and can now get the AR to simmer no problems. Im thinking of getting a thermometer lazer or something to measure the temp with. The second button is now but a ring but seems to have slowed right down. The AR had evaporated down quite alot so I did add some fresh hydrochloric not sure if this aided to slow down the digestion. Im still worried that if I get the AR too hot I will loose gold, I know Geo said that its not likely but I have read comments from your in regards to NOT BOIL AR containing gold I will read up some more but how hard does it have to boil before gold can be lost? it seems to take a long time to evaporate even with a large area of the AR ratio exposed (shallow but wide). Like so many before me I have gone at this the wrong way to begin with and not taken on enough before beginning. It just seems there is so much to take on and so little time I continue to read and learn and have come such a long way but still I have not even scratched the surface. I would just like to take this chance to thank each and everyone one here that has been so helpful please keep up the good work.
I guess Im on the right track I just came in after adding a larger button 1.28 grams that was flat lol. I also worked out why I could not get enough heat, the thermostat had been played with so I have adjusted it to provide more than enough heat and can now get the AR to simmer no problems. Im thinking of getting a thermometer lazer or something to measure the temp with. The second button is now but a ring but seems to have slowed right down. The AR had evaporated down quite alot so I did add some fresh hydrochloric not sure if this aided to slow down the digestion. Im still worried that if I get the AR too hot I will loose gold, I know Geo said that its not likely but I have read comments from your in regards to NOT BOIL AR containing gold I will read up some more but how hard does it have to boil before gold can be lost? it seems to take a long time to evaporate even with a large area of the AR ratio exposed (shallow but wide). Like so many before me I have gone at this the wrong way to begin with and not taken on enough before beginning. It just seems there is so much to take on and so little time I continue to read and learn and have come such a long way but still I have not even scratched the surface. I would just like to take this chance to thank each and everyone one here that has been so helpful please keep up the good work.
Geo
Well-known member
actually i said to keep it just below a boil.as the acid concentrates, the boiling point rises.if you keep increasing the heat to keep it boiling,the temperature will rise to the point that you will lose some gold.keep it hot but not boiling.
the trick to not having to expel free nitric is to not add too much to begin with. forget ratio's and pre-mixing.when you start the process, add the hcl needed for the process and heat. then slowly add the nitric in small increments. after each addition, wait for the reaction to stop and all red fumes to dissipate before adding more. look to make sure theres solids left before adding more.when the metal is dissolved, stop additions.
the trick to not having to expel free nitric is to not add too much to begin with. forget ratio's and pre-mixing.when you start the process, add the hcl needed for the process and heat. then slowly add the nitric in small increments. after each addition, wait for the reaction to stop and all red fumes to dissipate before adding more. look to make sure theres solids left before adding more.when the metal is dissolved, stop additions.
Hi Geo, Sorry didn't mean it in that way. I did understand that pushing it to boil would loose values hence why I was afraid to get it too hot. Is a simmer ok? at what point will the gold evaporate off? I didn't think that I had added too much nitric but if I'm correct in saying, Hoke said that 8ml of nitric can dissolve one gram of gold, and that being said and the fact my buttons are nearly all in solution I obviously did. I have learnt so much from my first few times and I really think that some better equipment would make things so much easier for me. I will follow your instructions next time heating HCl first before adding the NH03 I have seen today just how much difference heating the acid makes, seeing a button sitting with no reaction then heating and watching it dissolve before my eyes. As well as hearing it from some very knowledgeable people.
Geo
Well-known member
Harold_V
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Joined: February 25th, 2007, 10:58 pm
Location: Washington
January 28th, 2009, 10:55 pm
It would be reckless to base the operation on temperature. When you start evaporating, you'll come to realize that as the solution becomes more and more concentrated, it will tolerate more heat. There is no specific heat at which you should evaporate, aside from keeping the temperature below the boiling point of the solution.
Key to successful evaporation is to not allow the solution to boil----nor to evaporate too quickly. Start out with a low flame and observe. If you see little or no action, kick up the heat slightly-----and keep close watch on the vapors that come off. They must be colorless.
Sorry I'm not more help-------I never tied temperature with results----I just followed the instructions provided in Hoke's book, then made the change of adding a button of gold to assist in eliminating free nitric. That truly sets you free, and cuts short the amount of time spent evaporating. In the end, I evaporated to condense my solutions, not to eliminate nitric.
Harold
this is from an earlier thread and is a reply from Harold to another members question. i agree with this. try not to worry so much about a set temperature, just heat to below boiling and keep it there and you should be fine.
Active Member
Posts: 6487
Joined: February 25th, 2007, 10:58 pm
Location: Washington
January 28th, 2009, 10:55 pm
It would be reckless to base the operation on temperature. When you start evaporating, you'll come to realize that as the solution becomes more and more concentrated, it will tolerate more heat. There is no specific heat at which you should evaporate, aside from keeping the temperature below the boiling point of the solution.
Key to successful evaporation is to not allow the solution to boil----nor to evaporate too quickly. Start out with a low flame and observe. If you see little or no action, kick up the heat slightly-----and keep close watch on the vapors that come off. They must be colorless.
Sorry I'm not more help-------I never tied temperature with results----I just followed the instructions provided in Hoke's book, then made the change of adding a button of gold to assist in eliminating free nitric. That truly sets you free, and cuts short the amount of time spent evaporating. In the end, I evaporated to condense my solutions, not to eliminate nitric.
Harold
this is from an earlier thread and is a reply from Harold to another members question. i agree with this. try not to worry so much about a set temperature, just heat to below boiling and keep it there and you should be fine.
I do not understand why there is all this discussion about evaporation when you are using a gold button to consume excess nitric.
But while on that subject, you will always lose some gold to evaporation no matter the temperature, but keeping it low helps minimize losses. Try this experiment, put a gold solution on a hotplate at a very low temperature, just enough to give some evaporation with a watch glass or beaker of the same size on top of it. Once you have some condensation on the bottom of your watch glass use a piece of filter paper to collect some of it and test it with stannous chloride.
But while on that subject, you will always lose some gold to evaporation no matter the temperature, but keeping it low helps minimize losses. Try this experiment, put a gold solution on a hotplate at a very low temperature, just enough to give some evaporation with a watch glass or beaker of the same size on top of it. Once you have some condensation on the bottom of your watch glass use a piece of filter paper to collect some of it and test it with stannous chloride.
Ok thanks Geo and Harold, vaild points I must say. I will be trying to make sure I dont add too much NH03 from now on thats for sure.
Hi Oz, I was still on the subject as I dont have anymore buttons to add and just to try and learn more about how this all works. I understand the importance of stannous chloride but dont have any yet as I have not been able to get it or tin powder, and have been stock potting anything thought to have gold in it. I will be making a trip in next week to get this with my new equipment. Out of interest i will try the experiment you sugested.
Time to go and see if I can get this right :mrgreen:
Oz said:
Hi Oz, I was still on the subject as I dont have anymore buttons to add and just to try and learn more about how this all works. I understand the importance of stannous chloride but dont have any yet as I have not been able to get it or tin powder, and have been stock potting anything thought to have gold in it. I will be making a trip in next week to get this with my new equipment. Out of interest i will try the experiment you sugested.
Time to go and see if I can get this right :mrgreen:
Next trip to town stop by the hardware store, check the plumbing solder (lead free) 95% tin/5% antimony (no flux), I smash a piece flat, and heat in a little HCl, to make stannous chloride solution, I keep a little piece of tin metal in the bottle.
Cool thanks Butcher, I will do that. I just had alook at the AR and the remains of the second button was still there so I heated again and no reaction. I then added smb and all went well, there seems to be heaps of powder there can't wait to melt it 
. Thanks again for all your help everyone.
. Thanks again for all your help everyone.
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